Disposable ball point pen with eraser

ABSTRACT

A disposable ball point pen includes a tubular barrel having a forward tapered end through which the ball point is adapted to project. The ball point extends from an ink cartridge disposed internally of the barrel and in concentric relationship therewith. An eraser is at the rear end of the barrel and is solvent cemented therein upon being placed into engagement with the rear end of the ink cartridge with both parts serving to self-locate one another within the barrel interior. A longitudinally extending slot in the barrel permits the cartridge to be observed to thereby operate as an indicator of the ink supply. In this manner the barrel need not be transparent and may adapt a variety of colors and designs. A cap covers the ball point and tip of the barrel when the pen is carried in the pocket of the user. This cap may be removed and retained by a clip on the side of the rear of the barrel, thereby enabling the user to write with the pen and at the same time have ready access to the eraser where desired.

[ Sept. 3, 1974 'DISPOSABLE BALL POINT PEN WITH ERASER [76] Inventor: Marvin Kapilow, 8 Sound Rd., Rye,

[22] Filed: May 14, 1973 [21] Appl. No.: 360,069

[52] US. Cl. 401/195, 401/209 [51] Int. Cl 843k 7/06 [58] Field of Search 401/195, 104, 213,116, 401/117, 209, 217, 99-117 [56] References Cited UNITED STATES PATENTS 2,502,866 4/1950 Lust 401/209 X 2,538,155 1/1951 Henneman.... 401/82 2,569,374 9/1951 Felice 401/82 2,881,736 4/1959 Zepelovitch 401/104 3,380,296 4/1968 Malanga 401/195 X 3,458,267 7/1969 Larson 401/213 FOREIGN PATENTS OR APPLICATIONS 422,576 10/1966 Switzerland 401/213 1,303,561 8/1962 France 401/104 Primary Examiner-Lawrence Charles Attorney, Agent, or Firml(ane, Dalsimer, Kane, Sullivan and Kurucz [5 7 ABSTRACT A disposable ball point pen includes a tubular barrel having a forward tapered end through which the ball point is adapted to project. The ball point extends from an ink cartridge disposed internally of the barrel and in concentric relationship therewith. An eraser is at the rear end of the barrel and is solvent cemented therein upon being placed into engagement with the rear end of the ink cartridge with both parts serving to self-locate one another within the barrel interior. A longitudinally extending slot in the barrel permits the cartridge to be observed to thereby operate as an indicator of the ink supply. In this manner the barrel need not be transparent and may adapt a variety of colors and designs. A cap covers the ball point and tip of the barrel when the pen is carried in the pocket of the user. This cap may be removed and retained by a clip on the side of the rear of the barrel, thereby enabling the user to write with the pen and at the same time have ready access to the eraser where desired.

6 Claims, 3 Drawing Figures BACKGROUND OF THE INVENTION DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The illustrated ball point pen includes an outer Disposable ball point pens have suffered from a num- 5 barrel 12 having a rear open end 14 and a tapered forber of disadvantages which have prevailed over the years since their inception. In this connection, in order to protect the pockets and clothes of the pen user from ink stains, the pens have included mechanisms for retracting the ball point which inevitably increased the cost of the pen. The nature of a number of retraction mechanisms prevented the placement of an eraser at the rear of the barrel. Other pens were supplied with caps which covered the ball point and tip of the barrel. When it was desired to write, the user removed the cap and mounted it over the rear end of the barrel. Pens of this type could not be provided with erasers at their rear end but rather were merely plugged at this location.

In order to permit the user to observe the reserve of ink and interiorly mounted cartridge, the barrels were fabricated of transparent material. This did not permit the utilization of a wide variety of colors for the barrel. Pens that do utilize different colored barrels do not have any indicator of the reserve of ink in the cartridge. An unsatisfactory approach to this problem was the fabrication of a barrel from two pieces, the rear piece being of the selected color and the forward piece being transparent in order that the cartridge may be observed. A barrel of this type was inevitably asethetically unpleasant.

SUMMARY OF THE INVENTION A principle object of this invention is to provide a disposable ball point pen with an eraser and a protective cap for the ball point when carried by the user, which may be removed and simply placed on the pocket clip in order that the eraser may be readily available during writing.

Another object is to provide a pen of the above type in which an indicator is provided for the reserve of ink in the cartridge while permitting the barrel of the pen to be of any desired color throughout its length.

A further object is to provide a pen of the foregoing type employing only four parts including the barrel, eraser, cap and ball point cartridge assembly.

Other objects of the invention will become apparent from the following detailed description which is to be taken in conjunction with the accompanying drawing illustrating a somewhat preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is an elevational view of a ball point pen with eraser in accordance with the present invention with the protective cap shown associated with the pocket clip and in phantom protecting the ball point and tip of the pen barrel;

FIG. 2 is an enlarged fragmentary longitudinal sectional view taken along the line 22 of FIG. 1 showing the interior of the pen; and

FIG. 3 is a fragmentary longitudinal sectional view of the forward part of the pen showing the cap placed on the barrel tip and in protecting arrangement over the ball point.

ward end 16 terminating in a reduced opening 18. The barrel may be fabricated of relatively low cost material and in a successful application of the invention, it has been molded of polystyrene. As indicated in the foregoing, one of the significant attributes of this invention is the ability to adapt any desired color for the barrel 12. The reduced tapered end 16 includes three equally spaced recesses 20 formed from the male die of the mold which is provided with corresponding outwardly projecting ribs. These ribs mate with surfaces of the female die to take weight off the tip of the male die. In this manner damage or breaking of the male die is significantly reduced. Equally significant results are attained by placing the projecting ribs on the female die for engaging with the mating male die. The rear end 14 of the barrel 12 includes a pocket clip 22 which is most advantageously molded integrally on the barrel 12. It will be noted that the clip 22 does not include any undercuts and possesses a configuration predominantly of straight lines. As a result, a cam operated split mold is not necessary for molding and consequently a parting line is not present. In addition, it has been found that by controlling the shrinkage of the clip 22, and particularly its thicker base, the clips free end will shift closer to the outer surface of the barrel 12. The barrel 12 is also provided with a longitudinally extending slot 24 intermediate its ends, the purpose of which is to provide a visual indicator of the reserve of ink in the ball point ink cartridge assembly 26.

The ball point ink cartridge 26 may be of conventional construction and is supported interiorly of the barrel 12. Towards this end the ball point 28 projects through the forward barrel tip 16 out of opening 18 with the cartridge forward flange 38 engaging the inner beveled or tapered walls of the tip 16 to align the wall point 28 for writing purposes. The cartridge 32 of the assembly includes the ink supply which may be observed because of the transparent nature of the cartridge walls. Suitable structure perhaps in the form of laterally projecting arms 34, may be provided at the rear end of the cartridge 32 to further facilitate its alignment centrally and coaxially in relation to the barrel 12.

The pen 10 advantageously mounts a conventional eraser 36 disposed in the rear open end 14. This eraser 36 is adapted to engage with the rear end of the cartridge 32 thereby permitting both parts to self-align one another. In order to secure this relationship, the eraser 36 may be solvent cemented in place. Suitable solvents include methyl-ethylkeytone, methylene chloride, trichlorethylene and ethylenedichloride.

In order to protect the pockets and clothing of the pen user, the forward tip 16 is adapted to receive the cap 38 of sufficient resiliency and elasticity to laterally stretch and firmly grip the barrel walls. In this manner, the cap 38 will remain in place over the tip 28. When it is desired to remove the cap and write with the pen,

the cap need only be manually grasped and pulled off able, if desired. When the user has finished writing, the cap 38 may be removed from the clip 22 and placed on the barrel tip 16 over the ball point 38 once again.

Thus several aforenoted objects and advantages are most effectively attained, although a single, somewhat preferred embodiment of the invention has been disclosed and described in detail herein, it should be understood that this invention is in no sense limited thereby and its scope is to be determined by that of the appended claims.

What is claimed is:

1. A disposable ball point pen comprising:

a substantially opaque tubular molded one-piece plastic barrel having a rear end and a tapered forward end having a reduced opening, and an elongated longitudinally extending slot in the walls of the barrel intermediate the barrel ends;

a ball point cartridge assembly including a forward ball point projecting through said opening and forwardly from the tapered forward end, and a tubular transparent cartridge containing a supply of ink extending rearwardly from the ball point interiorly of the barrel; and

the barrel slot permitting visual observation of the ink in the transparent cartridge and consequently the reserve of ink in the cartridge remaining for writing.

2. The invention in accordance with claim 1, wherein an eraser is mounted interiorly of the barrel and projects rearwardly from the barrel rear end.

3. The invention in accordance with claim 2, wherein the eraser is solvent cemented to interior surfaces of the barrel.

4. The invention in accordance with claim 2, wherein the eraser and rear end of the cartridge engage one another to self locate the eraser and cartridge assembly with respect to the barrel.

5. The invention in accordance with claim 2, wherein the barrel includes a laterally extending pocket clip on the barrel rear end, the clip having a forwardly extending arm with a free end, and a cap on the barrel tapered end over the ball point when the pen is not in use, and the cap adapted to be removed from the barrel tapered end and mounted over the clip free end to expose the ball point for writing, and permit the eraser to be free of the cap when writing.

6. The invention in accordance with claim 5, wherein the cap is formed of resilient elastic material. 

1. A disposable ball point pen comprising: a substantially opaque tubular molded one-piece plastic barrel having a rear end and a tapered forward end having a reduced opening, and an elongated longitudinally extending slot in the walls of the barrel intermediate the barrel ends; a ball point cartridge assembly including a forward ball point projecting through said opening and forwardly from the tapered forward end, and a tubular transparent cartridge containing a supply of ink extending rearwardly from the ball point interiorly of the barrel; and the barrel slot permitting visual observation of the ink in the transparent cartridge and consequently the reserve of ink in the cartridge remaining for writing.
 2. The invention in accordance with claim 1, wherein an eraser is mounted interiorly of the barrel and projects rearwardly from the barrel rear end.
 3. The invention in accordance with claim 2, wherein the eraser is solvent cemented to interior surfaces of the barrel.
 4. The invention in accordance with claim 2, wherein the eraser and rear end of the cartridge engage one another to self locate the eraser and cartridge assembly with respect to the barrel.
 5. The invention in accordance with claim 2, wherein the barrel includes a laterally extending pocket clip on the barrel rear end, the clip having a forwardly extending arm with a free end, and a cap on the barrel tapered end over the ball point when the pen is not in use, and the cap adapted to be removed from the barrel tapered end and mounted over the clip free end to expose the ball point for writing, and permit the eraser to be free of the cap when writing.
 6. The invention in accordance with claim 5, wherein the cap is formed of resilient elastic material. 